ISA 12.04.04

Abstract

This standard applies to equipment made suitable for use in hazardous (classified) locations by pressurizing the use of a pressurizing system.&#160; <br>This standard applies both to equipment with and without an internal release of a flammable gas or vapor.&#160; <br>This standard does not apply to occupied portions of buildings such as ventilated or pressurized control rooms. <br><strong>Purpose</strong> <br>This standard provides guidance to those who employ pressurization for electrical equipment in hazardous (classified) locations, and should be used in conjunction with ANSI/NFPA 496, Purged and Pressurized Enclosures for Electrical Equipment .&#160; <br>This standard provides performance and test recommendations so that the enclosure and components mounted internally or protruding through the enclosure are unlikely to cause ignition of a surrounding flammable atmosphere.&#160; <br>This standard provides performance and test recommendations so that users are unlikely to be injured by rupture of the enclosure due to failure of the pressure -regulating devices in the PROTECTIVE GAS SUPPLY.